perf: replace synchronous OkHttp execute() with executeAsync()

Every coroutine dispatched to Dispatchers.IO is stamped BlockingContext at
dispatch time, so its worker releases its CPU permit and the shared kotlinx
scheduler grows past ncpu. A blocking execute() holds one of those threads for
the whole request; executeAsync() suspends until the response headers arrive
and releases the thread across the network round-trip.

Converts 27 call sites across quartz, commons, amethyst, nestsClient,
desktopApp and cli. executeAsync() was already the house pattern (63 existing
uses); these were the stragglers.

The withContext(Dispatchers.IO) wrappers are kept on purpose: executeAsync()
only suspends until headers, and reading the body (string()/bytes()) is still
a blocking read. Moving those onto Dispatchers.Default would hold its
core-sized CPU permits and starve the pool.

Four private helpers become suspend (decodeGifFrames, fetchFromNetwork,
downloadFirstChunk, extractFirstFrame). Each had exactly one caller, already
inside a withContext(Dispatchers.IO) in a suspend function, so nothing
propagates further.

desktopApp gains the okhttp-coroutines dependency (Apache-2.0, same version as
the okhttp it already ships).

Not converted: NipCommand.fetchText and RelayCommands.info in the CLI. amy is a
short-lived process whose main is runBlocking { dispatch(argv) } — there is no
long-lived dispatcher pool or UI thread to protect there, so blocking is by
design and making them suspend would only add risk.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

amethyst/src/main/java/com/vitorpamplona/amethyst/service/buzz/BuzzInviteMinter.kt

@@ -30,6 +30,7 @@ import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
+import okhttp3.coroutines.executeAsync
 
 /**
  * Mints a `block/buzz` workspace invite link by POSTing to the relay's **Buzz-specific**
@@ -86,7 +87,7 @@ object BuzzInviteMinter {
                     .post(bodyBytes.toRequestBody("application/json".toMediaType()))
                     .build()
 
-            okHttpClient(url).newCall(request).execute().use { response ->
+            okHttpClient(url).newCall(request).executeAsync().use { response ->
                 val payload = response.body.string()
                 val tree = runCatching { json.readTree(payload) }.getOrNull()
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/concord/ConcordCommunityImage.kt

@@ -30,6 +30,7 @@ import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.io.File
 import java.util.concurrent.ConcurrentHashMap
 
@@ -70,7 +71,7 @@ fun rememberConcordImageModel(
                     if (!cacheFile.exists()) {
                         val client = accountViewModel.httpClientBuilder.okHttpClientForImage(pointer.url)
                         val ciphertext =
-                            client.newCall(Request.Builder().url(pointer.url).build()).execute().use { resp ->
+                            client.newCall(Request.Builder().url(pointer.url).build()).executeAsync().use { resp ->
                                 if (!resp.isSuccessful) return@runCatching null
                                 resp.body.bytes()
                             }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/nests/room/theme/RoomFontLoader.kt

@@ -29,6 +29,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.io.File
 import java.security.MessageDigest
 
@@ -63,7 +64,7 @@ internal object RoomFontLoader {
             }.getOrNull()
         }
 
-    private fun ensureCached(
+    private suspend fun ensureCached(
         url: String,
         context: Context,
         clientFor: (String) -> OkHttpClient,
@@ -74,7 +75,7 @@ internal object RoomFontLoader {
 
         val client = clientFor(url)
         val request = Request.Builder().url(url).build()
-        client.newCall(request).execute().use { resp ->
+        client.newCall(request).executeAsync().use { resp ->
             if (!resp.isSuccessful) return null
             file.outputStream().use { out -> resp.body.byteStream().copyTo(out) }
         }

cli/src/main/kotlin/com/vitorpamplona/amethyst/cli/Context.kt

@@ -74,6 +74,7 @@ import kotlinx.coroutines.withTimeoutOrNull
 import okhttp3.Dispatcher
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.lang.management.ManagementFactory
 import java.util.concurrent.TimeUnit
 
@@ -304,7 +305,7 @@ class Context(
                         .url(relay.toHttp())
                         .header("Accept", "application/nostr+json")
                         .build()
-                okhttp.newCall(request).execute().use { resp ->
+                okhttp.newCall(request).executeAsync().use { resp ->
                     resp.body.string().let { Nip11RelayInformation.fromJson(it) }
                 }
             }.getOrNull()

cli/src/main/kotlin/com/vitorpamplona/amethyst/cli/commands/BuzzCommands.kt

@@ -57,6 +57,7 @@ import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
+import okhttp3.coroutines.executeAsync
 
 /**
  * `amy buzz …` — first-class access to the `block/buzz` workspace protocol, driving the
@@ -372,7 +373,7 @@ object BuzzCommands {
                         .url(url)
                         .get()
                         .build(),
-                ).execute()
+                ).executeAsync()
                 .use { it.code to it.body.string() }
         }
 
@@ -385,7 +386,7 @@ object BuzzCommands {
         withContext(Dispatchers.IO) {
             val builder = Request.Builder().url(url).post(body.toRequestBody(jsonMedia))
             if (auth != null) builder.header("Authorization", auth)
-            http.newCall(builder.build()).execute().use { it.code to it.body.string() }
+            http.newCall(builder.build()).executeAsync().use { it.code to it.body.string() }
         }
 
     /** `buzz post RELAY GID <text>` → publishes a kind-40002 stream message with an `h` tag. */

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/georelay/GeoRelayCsvLoader.kt

@@ -24,6 +24,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 
 /**
  * Fetches and parses the live georelays CSV so the [GeoRelayDirectory] can route
@@ -44,7 +45,7 @@ class GeoRelayCsvLoader(
                     .url(url)
                     .get()
                     .build()
-            okHttpClient(url).newCall(request).execute().use { response ->
+            okHttpClient(url).newCall(request).executeAsync().use { response ->
                 if (response.isSuccessful) {
                     GeoRelayDirectory.parseCsv(response.body.string())
                 } else {

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/lnurl/LightningAddressResolver.kt

@@ -30,6 +30,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.math.BigDecimal
 import java.math.RoundingMode
 import java.net.URLEncoder
@@ -191,7 +192,7 @@ class LightningAddressResolver(
         withContext(Dispatchers.IO) {
             try {
                 val request = Request.Builder().url(url).build()
-                httpClient.newCall(request).execute().use { response ->
+                httpClient.newCall(request).executeAsync().use { response ->
                     if (response.isSuccessful) {
                         response.body.string()
                     } else {
@@ -222,7 +223,7 @@ class LightningAddressResolver(
                 }
 
                 val request = Request.Builder().url(url).build()
-                httpClient.newCall(request).execute().use { response ->
+                httpClient.newCall(request).executeAsync().use { response ->
                     // Return body even on error — caller extracts "reason" or "message" from JSON
                     response.body.string()
                 }

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/lnurl/OkHttpLnurlEndpointResolver.kt

@@ -28,6 +28,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import kotlin.coroutines.cancellation.CancellationException
 
 /**
@@ -58,7 +59,7 @@ class OkHttpLnurlEndpointResolver(
             try {
                 val client = okHttpClient(url)
                 val request = Request.Builder().url(url).build()
-                client.newCall(request).execute().use { response ->
+                client.newCall(request).executeAsync().use { response ->
                     if (!response.isSuccessful) return@use null
                     val body = response.body.string()
                     val root = mapper.readTree(body) ?: return@use null

commons/src/jvmAndroid/kotlin/com/vitorpamplona/amethyst/commons/service/upload/BlossomClient.kt

@@ -36,6 +36,7 @@ import okhttp3.Request
 import okhttp3.RequestBody
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
+import okhttp3.coroutines.executeAsync
 import okio.BufferedSink
 import okio.source
 import java.io.File
@@ -149,7 +150,7 @@ open class BlossomClient(
                         paymentProof?.headers()?.forEach { (name, value) -> addHeader(name, value) }
                     }.put(body)
                     .build()
-            okHttpClient.newCall(request).execute().use { response ->
+            okHttpClient.newCall(request).executeAsync().use { response ->
                 if (response.code in MIRROR_UNSUPPORTED_CODES) {
                     throw BlossomMirrorUnsupportedException(serverBaseUrl, response.code)
                 }
@@ -208,7 +209,7 @@ open class BlossomClient(
                     .apply { authHeader?.let { addHeader("Authorization", it) } }
                     .get()
                     .build()
-            okHttpClient.newCall(request).execute().use { response ->
+            okHttpClient.newCall(request).executeAsync().use { response ->
                 check402(response, serverBaseUrl)
                 if (!response.isSuccessful) {
                     val reason = response.headers[BlossomServerUrl.REASON_HEADER] ?: response.code.toString()
@@ -237,7 +238,7 @@ open class BlossomClient(
                     .apply { authHeader?.let { addHeader("Authorization", it) } }
                     .delete()
                     .build()
-            okHttpClient.newCall(request).execute().use { it.isSuccessful }
+            okHttpClient.newCall(request).executeAsync().use { it.isSuccessful }
         }
 
     /**
@@ -256,7 +257,7 @@ open class BlossomClient(
                     .head()
                     .build()
             try {
-                okHttpClient.newCall(request).execute().use { it.isSuccessful }
+                okHttpClient.newCall(request).executeAsync().use { it.isSuccessful }
             } catch (e: CancellationException) {
                 throw e
             } catch (_: Exception) {
@@ -289,7 +290,7 @@ open class BlossomClient(
                     .addHeader(BlossomServerUrl.X_CONTENT_TYPE_HEADER, contentType)
                     .apply { authHeader?.let { addHeader("Authorization", it) } }
                     .build()
-            okHttpClient.newCall(request).execute().use { response ->
+            okHttpClient.newCall(request).executeAsync().use { response ->
                 BlossomPreflightResult(
                     accepted = response.isSuccessful,
                     status = response.code,
@@ -313,7 +314,7 @@ open class BlossomClient(
                     .url(BlossomServerUrl.report(serverBaseUrl))
                     .put(reportEventJson.toRequestBody("application/json".toMediaType()))
                     .build()
-            okHttpClient.newCall(request).execute().use { it.isSuccessful }
+            okHttpClient.newCall(request).executeAsync().use { it.isSuccessful }
         }
 
     /**
@@ -335,7 +336,7 @@ open class BlossomClient(
                     .url(url)
                     .get()
                     .build()
-            okHttpClient.newCall(request).execute().use { response ->
+            okHttpClient.newCall(request).executeAsync().use { response ->
                 if (response.isSuccessful) response.body.bytes() else null
             }
         }
@@ -368,7 +369,7 @@ open class BlossomClient(
                     .apply { authHeader?.let { addHeader("Authorization", it) } }
                     .put(body)
                     .build()
-            okHttpClient.newCall(request).execute().use { parseDescriptor(it, serverBaseUrl) }
+            okHttpClient.newCall(request).executeAsync().use { parseDescriptor(it, serverBaseUrl) }
         }
 
     private fun parseDescriptor(

desktopApp/build.gradle.kts

@@ -47,6 +47,7 @@ dependencies {
 
     // Networking
     implementation(libs.okhttp)
+    implementation(libs.okhttpCoroutines)
 
     // JSON
     implementation(libs.jackson.module.kotlin)

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/network/Nip11Fetcher.kt

@@ -30,6 +30,7 @@ import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.sync.withPermit
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.util.concurrent.ConcurrentHashMap
 
 /**
@@ -67,7 +68,7 @@ class Nip11Fetcher {
         }
     }
 
-    private fun fetchFromNetwork(url: NormalizedRelayUrl): Nip11RelayInformation? {
+    private suspend fun fetchFromNetwork(url: NormalizedRelayUrl): Nip11RelayInformation? {
         // FAIL-CLOSED: use currentClient() not getHttpClient()
         val client = DesktopHttpClient.currentClient()
         val httpUrl = url.toHttp()
@@ -78,7 +79,7 @@ class Nip11Fetcher {
                 .header("Accept", "application/nostr+json")
                 .build()
         return try {
-            client.newCall(request).execute().use { response ->
+            client.newCall(request).executeAsync().use { response ->
                 if (response.isSuccessful) {
                     val source = response.body.source()
                     source.request(MAX_RESPONSE_BYTES) // buffer up to limit

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/service/media/EncryptedMediaService.kt

@@ -25,6 +25,7 @@ import com.vitorpamplona.quartz.utils.ciphers.AESGCM
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.util.concurrent.ConcurrentHashMap
 
 /**
@@ -51,7 +52,7 @@ object EncryptedMediaService {
 
         return withContext(Dispatchers.IO) {
             val request = Request.Builder().url(url).build()
-            val response = httpClient.newCall(request).execute()
+            val response = httpClient.newCall(request).executeAsync()
             val encryptedBytes =
                 response.use {
                     if (!it.isSuccessful) throw RuntimeException("Download failed: ${it.code}")

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/service/media/ServerHealthCheck.kt

@@ -24,6 +24,7 @@ import com.vitorpamplona.amethyst.desktop.network.DesktopHttpClient
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 
 object ServerHealthCheck {
     enum class ServerStatus {
@@ -45,7 +46,7 @@ object ServerHealthCheck {
                         .url(url)
                         .head()
                         .build()
-                val response = DesktopHttpClient.currentClient().newCall(request).execute()
+                val response = DesktopHttpClient.currentClient().newCall(request).executeAsync()
                 response.use {
                     if (it.isSuccessful || it.code == 405) ServerStatus.ONLINE else ServerStatus.OFFLINE
                 }

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/service/media/VideoThumbnailCache.kt

@@ -27,6 +27,7 @@ import com.vitorpamplona.amethyst.desktop.network.DesktopHttpClient
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import org.jcodec.api.FrameGrab
 import org.jcodec.common.io.NIOUtils
 import org.jcodec.common.model.ColorSpace
@@ -122,7 +123,7 @@ object VideoThumbnailCache {
         }
     }
 
-    private fun extractFirstFrame(url: String): ImageBitmap? {
+    private suspend fun extractFirstFrame(url: String): ImageBitmap? {
         // For HLS we skip straight to ffmpeg — JCodec can't read m3u8.
         val isHls = url.contains(".m3u8", ignoreCase = true) || url.contains("/hls/", ignoreCase = true)
 
@@ -163,7 +164,7 @@ object VideoThumbnailCache {
      *
      * Cleans up zero-byte cache files on failure so a transient empty response isn't sticky.
      */
-    private fun downloadFirstChunk(url: String): Download? {
+    private suspend fun downloadFirstChunk(url: String): Download? {
         val hash = sha1Hex(url)
         val cached = File(downloadCacheDir, "$hash.mp4")
         if (cached.length() > 0L) return Download(cached, persistable = true)
@@ -171,7 +172,7 @@ object VideoThumbnailCache {
 
         var wrote = false
         var rangeHonored = false
-        DesktopHttpClient.currentClient().newCall(buildRangeRequest(url)).execute().use { resp ->
+        DesktopHttpClient.currentClient().newCall(buildRangeRequest(url)).executeAsync().use { resp ->
             if (!resp.isSuccessful && resp.code != 206) return null
             val contentType = resp.header("Content-Type")?.lowercase().orEmpty()
             if (contentType.startsWith("text/") || "html" in contentType) return null

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/ImportFollowListDialog.kt

@@ -82,6 +82,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import okhttp3.OkHttpClient
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.net.URLEncoder
 import java.util.concurrent.TimeUnit
 
@@ -141,7 +142,7 @@ private suspend fun resolveNip05Http(identifier: String): String? {
                     .readTimeout(10, TimeUnit.SECONDS)
                     .build()
             val request = Request.Builder().url(url).build()
-            val response = client.newCall(request).execute()
+            val response = client.newCall(request).executeAsync()
             response.use { resp ->
                 if (!resp.isSuccessful) return@withContext null
                 val body = resp.body.string()

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/media/AnimatedGifImage.kt

@@ -41,6 +41,7 @@ import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import org.jetbrains.skia.Bitmap
 import org.jetbrains.skia.Codec
 import org.jetbrains.skia.Data
@@ -131,10 +132,10 @@ fun AnimatedGifImage(
     }
 }
 
-private fun decodeGifFrames(url: String): GifFrames? =
+private suspend fun decodeGifFrames(url: String): GifFrames? =
     try {
         val request = Request.Builder().url(url).build()
-        val response = gifHttpClient.newCall(request).execute()
+        val response = gifHttpClient.newCall(request).executeAsync()
         val bytes = response.body.bytes()
 
         val skData = Data.makeFromBytes(bytes)

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/media/SaveMediaAction.kt

@@ -24,6 +24,7 @@ import com.vitorpamplona.amethyst.desktop.network.DesktopHttpClient
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import okhttp3.Request
+import okhttp3.coroutines.executeAsync
 import java.awt.FileDialog
 import java.awt.Frame
 import java.io.File
@@ -59,7 +60,7 @@ object SaveMediaAction {
         return withContext(Dispatchers.IO) {
             try {
                 val request = Request.Builder().url(url).build()
-                val response = httpClient.newCall(request).execute()
+                val response = httpClient.newCall(request).executeAsync()
                 response.use { resp ->
                     if (!resp.isSuccessful) return@withContext null
                     val total = resp.body.contentLength()

nestsClient/src/jvmAndroid/kotlin/com/vitorpamplona/nestsclient/OkHttpNestsClient.kt

@@ -31,6 +31,7 @@ import okhttp3.OkHttpClient
 import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
+import okhttp3.coroutines.executeAsync
 import java.io.EOFException
 import java.io.IOException
 import java.net.SocketException
@@ -167,7 +168,7 @@ class OkHttpNestsClient(
             val request = buildRequest()
             val response: Response =
                 try {
-                    httpClient(url).newCall(request).execute()
+                    httpClient(url).newCall(request).executeAsync()
                 } catch (e: SocketException) {
                     transportError = e
                     if (++transportAttempts >= MAX_TRANSPORT_RETRIES) throw NestsException("Failed to reach $url", e)

quartz/src/jvmAndroid/kotlin/com/vitorpamplona/quartz/nip03Timestamp/okhttp/OkHttpBitcoinExplorer.kt

@@ -58,7 +58,7 @@ class OkHttpBitcoinExplorer(
                 .get()
                 .build()
 
-        return client.newCall(request).execute().use {
+        return client.newCall(request).executeAsync().use {
             if (it.isSuccessful) {
                 Log.d("OkHttpBlockstreamExplorer") { "$baseAPI/block/$hash" }